If the fracture is acute antemortem or postmortem then the fracture margins should be sharp without sclerosis. Changes in both findings suggest that the patient was alive and that some time had passed since the injury.
Method: postmortem magnetic resonance imaging (MRI)
Premise:
(1) Bone marrow edema and hemorrhage occurs at the site of fracture if the person is alive.
(2) Blood circulation must be present for bone marrow edema and hemorrhage to occur.
(3) Bone marrow edema and hemorrhage should be absent in fractures occurred after death.
Signal changes seen with ante-mortem fractures:
(1) high-signal intensity on STIR (short tau inversion recovery)
(2) low-signal intensity on T1 weighted (T1W) images
Another finding that should be absent in post-mortem fractures is hemorrhage and/or edema in the soft tissues adjacent to the fractures.
One unanswered question is how long the interval has to be between death and the fracture. In the case presented by the authors the interval between death (by electrocution) and the cause of fracture (a fall from height) was less than a minute..
Limitations:
• The size of the study was limited and the results need to be verified in larger series.
• MRI is fairly expensive.
